Making a gateway is a nearly instantaneous process. Plus we've seen Lews Therin make up to six gateways at a time.

Over the span of a minute, he could probably make 36 gateways into a particular area - say 5 miles by 5 miles square.

If disrupting a gateway is a difficult art - as RJ seems to indicate, how is a single defender going to move around fast enough to block 36 gateways opening all over the area being defended?

In fact, if he has to see what he's doing, he would probably have to Travel himself to get to gateways that are forming more than a few hundred yards from his current location.

If an attacker spins 6 gateways simultaneously, to open at intervals of 1 mile from one another, I find it difficult to see how his opponent is going to block all of them. Especially if blocking a gateway is difficult to achieve, and requires a heck of a lot of concentration.

The only way I can see it working, is if some kind of defensive ward can be placed over an area, blocking it from the Pattern. And that this ward can then be attacked or penetrated by an opponent, if he is skilled enough. In turn, the defender can bolster the ward and repel the attempts to penetrate it by the attacker, if HE is skilled enough.

Thus, the battle is taking place at many levels, as RJ indicated.